Processes for producing low chlorophyll, high polar lipid compositions from algal oils and extracts

ABSTRACT

A method for producing highly bioavailable oil compositions from biomasses and, in particular, autotrophic algal biomasses, and providing characterized and clarified mass balance breakdowns and component products therefrom without loss of significant mass in an extraction such as a liquid-liquid extraction, polarity segregation and use of mechanical cartridges.

REFERENCE TO RELATED APPLICATIONS

This application is a Continuation Application of U.S. application Ser. No. 17/718,009, which is a Continuation-in-part Application of U.S. application Ser. No. 16/953,978, filed Nov. 20, 2020 and issued as U.S. Pat. No. 11,298,387 on Apr. 12, 2022. This application also claims priority to U.S. application Ser. No. 17/975,231, filed Oct. 27, 2022, which is a Divisional Application of U.S. application Ser. No. 17/718,009. This application also claims priority to International Application No. PCT/US2022/034537 and International Application No. PCT/US2022/034512, both of which were filed on Jun. 22, 2022, and both of which have the same priority date of Apr. 11, 2022. All of the above U.S. Patents, U.S. Patent Applications, and International Applications are incorporated herein by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

BACKGROUND

Long chain Omega-3 oils are vital to human health and deficits in them can have serious, negative health impacts. These range from developmental deficiencies in brain and neural networks to our cardiovascular health, and more. Omega-3 oils are in high demand today due to supply limitations in aquaculture, fisheries, and other marine sources, at latest report, being able to supply only approximately 0.8 million tons of Omega-3 fatty acids per year for human consumption. This is well below the current human nutritional demand of 1.4 million tons required to supply the global population with 500 mg Omega-3 fatty acids daily and will be further exacerbated by population growth. Omega-3 fatty acids deficiencies have been observed worldwide, and particularly affect populations located in North America, central Europe, the Middle East, India, Brazil, and the United Kingdom, with regional and socioeconomic differences seen within these countries. There are three major Omega-3 fatty acids found in nature. Alpha linoleic acid (ALA), with 18 carbons and 3 double bonds, can be found, e.g., in flax seeds, soybean oil and olives. Docosahexaenoic acid (DHA) with 22 carbons and 6 double bonds, and Eicosapentaenoic acid (EPA), with 20 carbons and 5 double bonds, are only produced in aquatic species (algae) and can be extracted from krill or fish that eat the algae, or from the algae themselves.

“Working algae”, i.e., algae grown using sunlight or artificial light using photosynthesis comprise mostly polar lipids, which fall into the categories of glycolipids and phospholipids. By their nature, these species have hydrophobic tails and a polar (hydrophilic) head—i.e., they are essentially exotic natural detergents. These materials have exceptionally high bioavailability, and thus, readily enter the human bloodstream to deliver the above-mentioned health benefits. Various of these valuable materials have proven not found to be naturally produced in other sources, such sources may be of questionable sustainability, or have proven to be difficult to feasibly access. Moreover, extracting them from microalgae efficiently and in their pure, natural, bioavailable form, has not previously been effectively accomplished in a commercially successful manner, as existing commercial products have been hampered by an unattractive appearance, odor and texture. While having a higher bioavailablity, algae extracts have traditionally included components which give the extracted oil an overall, very dark, nearly black-ish, appearance, and a highly viscous feel, making them resemble an unattractive tar-like black solid, which remains relatively low in concentrations of Omega-3 fatty acids .

Additionally, existing crude products have previously not been able to be fully or adequately analyzed and characterized. Indeed, despite decades of study, a fully characterized mass balance has not been accomplished or published without either reporting inclusions of high levels (e.g., up to 10% or more) “unknowns” or “unidentified” materials, or by reporting results only “by difference” and putting such essentially uncharacterized materials in a bucket labelled simply as “carbohydrates”, for example. This is especially undesirable in the case of nutraceutical and pharmaceutical products.

In summary, a process for producing a highly bioavailable, high concentration Omega-3 containing, EPA-containing, high in polar lipids, especially glycolipids composition, which presents as a low viscosity, low chlorophyll content light amber to dark amber colored oil for use in nutraceutical and pharmaceutical products, the contents of which are fully, or nearly fully characterized, is currently unavailable, yet highly desirable. Moreover, a method to obtain such highly desirable compositions directly from plentiful, highly sustainable algae sources, would be ideal.

SUMMARY

The present disclosure describes a solution to the above problems by utilizing separation processes which may include liquid-liquid reactors or mechanical cartridges to extract oil extracts from microalgal biomass. The crude extract is then fractionated into clean, well-characterized fractions, e.g., polar lipids, polysaccharides, and carotenoids, with high efficiency and very high recovery. By virtue of the innovative fractionation process of the disclosure, a full mass balance of the oil extract, and of the entire algal biomass, is now possible.

In one embodiment, the disclosed process includes a method for production of a low chlorophyll content oil composition comprising the steps of obtaining a suitable algal biomass such as an algal paste or dried powder; extraction of the algal biomass with a polar solvent such as an alcohol like ethanol to form an extract of algal lipids; extraction of the obtained extract with, e.g., an organic solvent such as the hydrocarbons hexane or heptane, to separate the fraction of non-polar lipids, transferring the, e.g., alcohol layer containing pigments and polar lipids to a further stage of processing; adding water to the, e.g., alcohol layer extracted, e.g., with heptane, and then its sequential extraction with, e.g., heptane, to extract the pigment fraction and separating out the polar lipid fraction. Polar lipids can then be obtained from the fraction containing them by evaporation, and pigments can also be obtained by evaporation of the fraction containing them.

In an alternative embodiment, the disclosed process includes a method for production of a low chlorophyll content oil composition comprising the steps of obtaining an algal biomass which includes both polar and non-polar lipid fractions and also has a chlorophyll concentration. The method further includes using polarity characteristics of the polar and non-polar lipid fractions to segregate polar from non-polar components in the algal biomass, including substantially segregating the chlorophyll concentration with the non-polar lipid fraction. Additional steps include bleaching out substantially all the chlorophyll concentration from the non-polar containing fraction; and re-combining the polar and non-polar lipid fractions to produce the low chlorophyll-content LC-PUFA oil composition.

The above process embodiments produce an attractive composition for use in both the nutraceutical and pharmaceutical fields, particularly in terms of reduced opacity and viscosity.

In a related embodiment, a method of fractionating and clarifying algal biomass into its clean, precisely characterized components of Liquid Extracted Biomass, i.e., the residual post-extraction biomass (“LEA’), polar lipids, pure neutral lipids, chlorophyll, polysaccharides, carotenoids with high recovery of the total, and reporting a full algal biomass balance, is provided. The method comprises the steps of obtaining an algal biomass such as a paste or powder; extraction of the algal biomass with a polar solvent such as an alcohol like ethanol to form, e.g., an alcoholic extract of algal lipids; extraction of the obtained, e.g., alcoholic extract with, e.g., an organic solvent such as the hydrocarbons hexane or heptane, to separate the fraction of non-polar lipids, transferring the, e.g., alcohol layer containing pigments and polar lipids to a further stage of processing; adding water to the, e.g., alcohol layer extracted, e.g., with heptane, and then its sequential extraction with, e.g., heptane, to extract the pigment fraction and separating out the polar lipid fraction.

In an additional aspect, a method is provided for the extraction of biomass oils, which include, but are not limited, to lipids, chlorophyl, saccharides, carotenoids and CBD from a dry, preferably powdered, biomass. The method includes the steps of obtaining a mechanical cartridge or extraction column with an inner bore and inlet and outlet ends configured to permit solvent flow. The mechanical cartridge is capable of being heated/cooled and pressurized and of containing heated/cooled and pressurized solvent at ranges sufficient to separate the target biomass oil from the dry biomass. For example, the operating conditions permit the operator to melt lipids, thus allowing for their extraction from the dry biomass in which they were contained. The mechanical cartridge itself is filled with dried biomass and the mechanical cartridge can be heated/cooled to a predetermined temperature, typically between −30 C to 150 C range. Temperature controlled solvent is pumped through the dry biomass filled mechanical cartridge at a temperature, pressure, retention time and flow rate sufficient to remove the targeted biomass oils. For lipid containing biomasses, the elevated temperature solvent melts the lipids in the lipids-containing portion of the dried biomass and thereby extracting the lipids in liquid form from portions of the biomass retained in the mechanical cartridge under the same conditions.

The disclosure further relates to a bioavailable, LC-PUFA-, Omega-3-, EPA-, polar lipids- and glycolipids/phospholipid-rich composition especially suitable for use in nutraceutical and pharmaceutical compositions, which can be considered as health or medical compositions, and as having other valuable end products. Starting material for this composition, may be derived from algae as described herein. In one embodiment, a composition is disclosed including a polar lipids fraction of a concentration of total lipids of at least 20% of the total lipids by weight %; wherein the polar lipids fraction comprises at least 40% glycolipids by weight; and wherein the composition comprises no greater than 4% of its weight % as a chlorophyll concentration.

The composition, prepared as described above, with its total lipids having a fraction of at least 20 wt. % polar lipids, and its polar lipids having a fraction of at least 40 wt. % glycolipids, but the composition having less than a 4 wt. % chlorophyll fraction, may further include formulations with additive non-polar lipids and/or nutraceutical oils such as DHA, Esters or salts of EPA or DHA (or mixtures thereof) or other beneficial additives as more fully described below, which also assist in providing for certain beneficial combinations of a more bioavailable, nutrient rich, lighter color, lower viscosity, oil.

These features and other features of the present disclosure will be discussed in further detail in the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 discloses a schematic diagram of extraction process steps for an exemplary method of preparation of the oil of an embodiment of the disclosure.

FIG. 2 is a photographic depiction of an embodiment of a composition of the disclosure made according to the exemplary method as set forth in FIG. 1 , having a desired target LC-PUFA-, polar lipid-, Omega-3-, EPA- and glycolipid-rich and chlorophyll-reduced concentration, with bioavailability, color and viscosity of a desired oil composition, embodiments of which are disclosed herein.

FIG. 3 is a photographic depiction of a powder obtained by an embodiment of a process of the disclosure made up substantially of non-lipids components comprising, e.g., polysaccharides contained in the crude ethanolic algal extract made according to an embodiment of the process as described herein.

FIG. 4 is a graphical depiction of a spectral characterization of an embodiment of an ethanolic extract of Nannochloropsis and products after pigments removal as discussed in Example 1.

FIG. 5 is a graphical depiction of a UV-Visible spectral characterization of an embodiment of an algal extraction as discussed in Example 2.

DETAILED DESCRIPTION

The following detailed description illustrates the claimed disclosure by way of example and not by way of limitation. This description will clearly enable one skilled in the art to make and use the claimed disclosure, and describes several embodiments, adaptations, variations, alternatives, and uses of the claimed disclosure. Additionally, it is to be understood that the claimed disclosure is not limited in its application to the details and compositions specifically set forth in the following description or illustrated by means of the figures. The claimed disclosure is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

As used herein, the term “lipids” means various organic compounds that are insoluble in water. They include fats, waxes, oils, hormones and certain components of membranes.

As used herein, the term “polar lipids” means amphiphilic lipids with a hydrophilic head and a hydrophobic tail. Examples of polar lipids include phospholipids and glycolipids.

As used herein the term “non-polar lipids” means fatty molecules wherein the charge distribution is largely evenly distributed, and the molecules do not have positively and negatively charged ends. Examples of non-polar lipids include triglycerides of the various fatty acids in the oil (e.g., EPA, palmitoleic acid and others).

As used herein, the term “biomass” means the total mass of biological organisms, including, e.g., plants and microorganisms, and can include, from a biological perspective, cellulose, lignin, lipids, sugars, and proteins. While aspects of the process of the invention are directly relevant to extraction, fractionation and clarification of algal biomass, “biomass” should be considered to include other types of organisms such as those of fungal or other origin, or “biomass” from a given area or volume, unless expressly limited to algal biomass as the sole or primary source.

As used herein, the acronyms “EPA” and “DHA” refer to eicosapentaenoic acid and docosahexaenoic acid, respectively, as well as the salt and ethyl ester forms of each compound. In its naturally-occurring acid form, EPA is a twenty-carbon unsaturated chain culminating in a carboxylic acid functional group. However, one of ordinary skill in the art appreciates that natural variants of this acidic form include an alkaline salt, in which the deprotonated carboxylic acid is stabilized by a counter anion, and an ethyl ester, in which two more carbons are singly covalently bonded to the sp³-hybridized oxygen so as to result in an ester. In the case of the ethyl ester form, then, EPA has twenty-two carbons. Similarly, DHA in its acidic form is a twenty-two-carbon unsaturated chain culminating in a carboxylic acid functional group, and is understood to have natural variants including the alkaline salt and ethyl ester form. In the ethyl ester form, consequently, DHA has twenty four carbons. Alkaline salt forms of these compounds may manifest spontaneously as a result of particular chemical environments in which they are present. The transformation to the ethyl ester variants is similarly facile, and these variants are also used as medicants to treat, for example, high blood triglyceride levels. Any use of the acronyms “EPA” and “DHA” in the present application should not be construed to exclude the alkaline salt or ethyl ester variants of either compound unless their exclusion is made explicit.

To produce the disclosed embodiments of clarified compositions of an algal biomass, an algal paste, which presents as a dark green or even black, highly viscous oil can be obtained using standard steps known by those of ordinary skill in the industry. See, e.g., the production of the algal paste and useful varieties of algae employable, as described in U.S. Pat. No. 8,591,912 B1 (hereinafter “Kadam and Goodall”), incorporated herein by reference and additionally discussed herein. Additionally, such an algal biomass useful for extraction may be dry and presented in the form of an algal powder or other suitable form.

Procedures for obtaining the algal biomass extract, and starting algae and extraction procedures for preparing the algal biomass can include the following steps, as part of an extraction:

Obtain or prepare a biomass such as an algal paste or powder, e.g., prepared from the algal paste from an appropriate species suitable for producing such a target biomass. For example and without limitation, dry algal powder can be prepared from an algae paste by, e.g., a drum dryer, a powder dryer, a refractance window dryer, a freeze dryer, an oven, etc. by procedures known to those skilled in such drying arts. In general, microalgae can be harvested by conventional means (including, but not limited to filtration, air flotation and centrifugation) and the algal paste generated by concentrating the harvested microalgae to the desired weight % of solids. In certain embodiments, the microalgae used with the methods of the invention are members of one of the following divisions: Chlorophyta, Cyanophyta (Cyanobacteria), and Heterokontophyta. In certain embodiments, the microalgae used with the methods of the invention are members of one of the following classes: Bacillariophyceae, Eustigmatophyceae, and Chrysophyceae. In certain embodiments, the microalgae used with the methods of the invention are members of one of the following genera: Nannochloropsis, Chiarella, Dunaliella, Scenedesmus, Selenastrum, Oscillatoria, Phormidium, Spirulina, Amphora, and Ochromonas. Non-limiting examples of microalgae species that can be used with the methods of the present invention include: Achnanthes orientalis, Agmenellum spp., Amphiprora hyaline, Amphora coffeiformis, Amphora coffeiformis var. linea, Amphora coffeiformis var. punctata, Amphora coffeiformis var. taylori, Amphora coffeiformis var. tenuis, Amphora delicatissima, Amphora delicatissima var. capitata, Amphora sp., Anabaena, Ankistrodesmus, Ankistrodesmus falcatus, Boekelovia hooglandii, Borodinella sp., Botryococcus braunii, Botryococcus sudeticus, Bracteococcus minor, Bracteococcus medionucleatus, Carteria, Chaetoceros gracilis, Chaetoceros muelleri, Chaetoceros muelleri var. subsalsum, Chaetoceros sp., Chlamydomas perigranulata, Chlorella anitrata, Chlorella antarctica, Chlorella aureoviridis, Chlorella candida, Chlorella capsulate, Chlorella desiccate, Chlorella ellipsoidea, Chlorella emersonii, Chlorella fusca, Chlorella fusca var. vacuolata, Chlorella glucotropha, Chlorella infusionum, Chlorella infusionum var. actophila, Chlorella infusionum var. auxenophila, Chlorella kessleri, Chlorella lobophora, Chlorella luteoviridis, Chlorella luteoviridis var. aureoviridis, Chlorella luteoviridis var. lutescens, Chlorella miniata, Chlorella minutissima, Chlorella mutabilis, Chlorella nocturna, Chlorella ovalis, Chlorella parva, Chlorella photophila, Chlorella pringsheimii, Chlorella protothecoides, Chlorella protothecoides var. acidicola, Chlorella regularis, Chlorella regularis var. minima, Chlorella regularis var. umbricata, Chlorella reisiglii, Chlorella saccharophila, Chlorella saccharophila var. ellipsoidea, Chlorella salina, Chlorella simplex, Chlorella sorokiniana, Chlorella sp., Chlorella sphaerica, Chlorella stigmatophora, Chlorella vanniellii, Chlorella vulgaris, Chlorella vulgaris fo. tertia, Chlorella vulgaris var. autotrophica, Chlorella vulgaris var. viridis, Chlorella vulgaris var. vulgaris, Chlorella vulgaris var. vulgaris fo. tertia, Chlorella vulgaris var. vulgaris fo. viridis, Chlorella xanthella, Chlorella zofingiensis, Chlorella trebouxioides, Chlorella vulgaris, Chlorococcum infusionum, Chlorococcum sp., Chlorogonium, Chroomonas sp., Chrysosphaera sp., Cricosphaera sp., Crypthecodinium cohnii, Cryptomonas sp., Cyclotella cryptica, Cyclotella meneghiniana, Cyclotella sp., Dunaliella sp., Dunaliella bardawil, Dunaliella bioculata, Dunaliella granulate, Dunaliella maritime, Dunaliella minuta, Dunaliella parva, Dunaliella peircei, Dunaliella primolecta, Dunaliella salina, Dunaliella terricola, Dunaliella tertiolecta, Dunaliella viridis, Dunaliella tertiolecta, Eremosphaera viridis, Eremosphaera sp., Effipsoidon sp., Euglena spp., Franceia sp., Fragilaria crotonensis, Fragilaria sp., Gleocapsa sp., Gloeothamnion sp., Haematococcus pluvialis, Hymenomonas sp., Isochrysis aff. galbana, Isochrysis galbana, Lepocinclis, Micractinium, Micractinium, Monoraphidium minutum, Monoraphidium sp., Nannochloris sp., Nannochloropsis salina, Nannochloropsis sp., Navicula acceptata, Navicula biskanterae, Navicula pseudotenelloides, Navicula pelliculosa, Navicula saprophila, Navicula sp., Nephrochloris sp., Nephroselmis sp., Nitschia communis, Nitzschia alexandrina, Nitzschia closterium, Nitzschia communis, Nitzschia dissipata, Nitzschia frustulum, Nitzschia hantzschiana, Nitzschia inconspicua, Nitzschia intermedia, Nitzschia microcephala, Nitzschia pusilla, Nitzschia pusilla elliptica, Nitzschia pusilla monoensis, Nitzschia quadrangular, Nitzschia sp., Ochromonas sp., Oocystis parva, Oocystis pusilla, Oocystis sp., Oscillatoria limnetica, Oscillatoria sp., Oscillatoria subbrevis, Parachlorella kessleri, Pascheria acidophila, Pavlova sp., Phaeodactylum tricomutum, Phagus, Phormidium, Platymonas sp., Pleurochrysis carterae, Pleurochrysis dentate, Pleurochrysis sp., Prototheca wickerhamii, Prototheca stagnora, Prototheca portoricensis, Prototheca moriformis, Prototheca zopfii, Pseudochlorella aquatica, Pyramimonas sp., Pyrobotrys, Rhodococcus opacus, Sarcinoid chrysophyte, Scenedesmus armatus, Schizochytrium, Spirogyra, Spirulina platensis, Stichococcus sp., Synechococcus sp., Synechocystisf, Tagetes erecta, Tagetes patula, Tetraedron, Tetraselmis sp., Tetraselmis suecica, Thalassiosira weissflogii, and Viridiella fridericiana.

Preferred algal species are those, e.g., rich in LC-PUFA oil sources. Exemplary of such algae strains are strains from Nannochloropsis, Chlorella or Trachydiscus minutus algal varieties.

The algal paste or other suitable form of algal biomass can be processed as follows: extract, e.g. with a polar solvent such as an alcohol, including, ethanol to form, e.g., an alcoholic extract of algal lipids with a low water content (forming, e.g., an ethanolic extract of Nannochloropsis lipids (hereinafter referred to for brevity as “EEN”); extract the obtained EEN with, e.g., an organic solvent such as the hydrocarbons hexane or heptane to separate out the fraction of non-polar lipids (e.g., triglycerides, waxes, carotenes), thus forming a “non-polar lipid fraction” (F#1 of FIG. 1 ) in the heptane layer. The alcohol layer containing pigments and polar lipids can be transferred to a further stage of processing. See FIG. 1 . Other solvents such as carbon dioxide or carbon dioxide ethanol mixes may be considered.

The next stage of processing can involve adding water to the polar solvent layer extracted, e.g., with heptane and then its sequential extraction with, e.g., heptane, to extract the pigment fraction (see FIG. 1 , heptane layer, F#3) and separating out the polar lipid fraction (see FIG. 1 , water-alcohol layer, F#2). Polar lipids can be obtained from the F#2 fraction by evaporation, and pigments can be obtained by evaporation of the F#3 fraction. The F#1 layer may contain an amount of chlorophylls and carotenoids, which can be removed by methods known to those skilled in the art, e.g., methods known for the production of edible oils. Examples of these methods include adsorption-filtration using silica gel, bleaching clays such as B80, T41, activated carbon, and others. As a result of the selective removal of chlorophyll from the F#1 fraction, in this embodiment, a largely clear to dark amber, including reddish, somewhat liquid to semi-solid oil can be obtained.

In an alternative embodiment, the method for production of a low chlorophyll content oil composition, via the extraction of algal biomass such as algal paste or powder, so obtained includes both polar and non-polar lipid fractions and also has a chlorophyll concentration. Polarity characteristics of the polar and non-polar lipid fractions of the biomass are used to segregate polar from non-polar components in the algal biomass, including substantially segregating the chlorophyll concentration with the non-polar lipid fraction. As illustrated in Example 2 below, additional steps include bleaching out substantially all the chlorophyll concentration from the non-polar containing fraction; and re-combining the polar and non-polar lipid fractions to produce the low chlorophyll-content oil composition.

In addition to the low chlorophyll-content aspect of the composition, the present invention also provides for isolated oil derived from algae which are rich in LC-PUFAs, including at least one Omega-3 fatty acid such as, but not limited to, EPA or DHA, at least partially in the form of whole and unhydrolyzed phospholipids and whole and unhydrolyzed glycolipids extracted by the above processes. The oil produced by such process is unexpectedly high in polar lipids such as phospholipids and glycolipids. It is known that krill oil, by virtue of the contained phospholipids (a polar lipid) has higher bioavailability in mammals than does fish oil, which comprises almost exclusively neutral lipids (triglycerides). See, Jan Philipp Schuchardt et al., Lipids in Health and Disease 2011, 10:145. Remarkably, the oils extracted from algae such as Nannochloropsis using the inventive methods showed bioavailability to mammals that surpassed even krill oil.

In another embodiment of the lipid-extraction aspect of the invention, the inventors have created a process for the extraction of biomass oils, which include, but are not limited to lipids, chlorophyll, saccharides, carotenoids and CBD utilizing a heated (or in certain circumstances, cooled), pressurized mechanical cartridge or extraction column to extract, e.g., in the case of lipids, by melting them from lipid-containing dry, preferably powdered biomasses (see above for various methods of producing powdered biomasses). Such lipid-containing powdered biomasses to which this aspect applies include, but are not limited to, algal biomasses, such as the preferred sources (autotrophic, Nannochloropsis-derived, etc. algal biomasses described elsewhere in this application).

The biomass oil, e.g., lipid extraction, using a pressurized, temperature-controlled mechanical cartridge to, e.g., melt the lipids contained in a dried biomass, has a number of advantages. For instance, its use provides for a significant reduction in the time required for the lipid extraction to reach completion. The use of the mechanical cartridge has been shown to reduce the processing time to one-third that required when using a standard reactor/mixing tank. For another, this process allows for a substantial reduction in the solvent required for the extraction. The use of the mechanical cartridge has been shown to reduce the amount of solvent required to one-fourth that required when using the standard reactor/mixer

The cartridge or extraction column selected is dimensioned to have an inner bore and inlet and outlet ends configured to permit containment of the dry biomass and also to permit and regulate solvent flow. The inner diameter of the mechanical cartridge is constructed of a material, preferably stainless steel, capable of being heated and pressurized and of containing heated and pressurized solvent at ranges sufficient to melt and separate out lipids (or otherwise extract out a target oil based on differentials in reaction to temperature and pressure). The inner diameter of the cartridge can preferably be between 25 and 1000 mm and a straight length, not including the inlet and outlet connections, of between 100 to 1000 mm. More preferably, these can be between 300 and 500 and 150 mm to 300 mm, respectively. Even more preferably these are 400 mm and 200 mm respectively. The inlet and outlet ends of the mechanical cartridge, which provide for and regulate solvent flow through the inside of the cartridge and through the powdered biomass contained within, include grates, screens, gates, etc. which allow for control and regulation of rates of flow and retention time for the solvent. They also can be used to limit the leftover solid material from passing out of the mechanical cartridge.

The material, and its physical form, chosen to fill the cartridge will depend to a degree on the target biomass. For algal biomass as a target, the cartridge can be filled with a lipid-containing portion of a dried, preferably powdered, biomass and is heated to a predetermined temperature to facilitate the lipid melting. Non-limiting examples of ways to heat the cartridge itself include jacketing the cartridge, passing a heating fluid around its exterior, immersing it in a heating solution, and via electrical resistance or induction.

In this embodiment, after the cartridge is filled with a lipid-containing portion of a powdered biomass, preheated solvent is pumped through the cartridge at a temperature, pressure, retention time and flow rate optimized to melt the lipids in the lipids-containing portion of the powdered biomass, thereby extracting the lipids in liquid form from portions, e.g., chlorophyll-containing content, retained in the cartridge under the same conditions.

The solvent used in the cartridge method may be any applicable solvent. Non-limiting examples include alcohols such as ethanol, hexane, heptane, carbon dioxide or solvent mixtures. Moreover, the method is applicable to a full range of lipid profile, i.e., polar to non-polar for the associated crude extraction from a dried biomass.

An operating principle for the use of the mechanical cartridge is its allowance of extraction with solvents at targeted, e.g., for algal biomasses, elevated temperatures, and pressures. Preferred temperatures for the solvents can be in a range between −30 C degrees C. and 150 degrees C. For lipid extraction, more preferably between 70 degrees C. and 110 degrees C., and even more preferably 90 degrees C. Preferred operating pressure of the solvent is between 5 bar and 100 bar, more preferably between 25 and 50 bar, and even more preferably is 30 bar. As noted, depending on the material to be extracted, the solvent used, and the biomass from which the target material is being extracted, even a cooled solution could similarly be employed for suitable biomass material extraction in which a cooled solvent is more advantageous.

Such mechanical cartridge lipid extractions are readily combined with further processing, e.g., via the approaches presented in Examples 1 and 2 below.

EXAMPLES

The following non-limiting examples are illustrative of the invention, both for clarifying and determining specific components of the oil composition, and for producing the LC-PUFA-rich and low-chlorophyll, low-polysaccharide-containing oils as further described herein:

Example 1:

2.1 Process protocol for this Example (as referred to in FIG. 1 )

-   -   1) 100 g of Nannochloropsis algal paste (22-27% of solids in         water) was weighed out. (Stage 1, FIG. 1 )     -   2) The algae paste was placed in a 2 L flask and 850 ml of         alcohol was added. (Stage 1, FIG. 1 )     -   3) The algae was extracted for 45 min at a temperature of 70° C.         with vigorous stirring. (Stage 1, FIG. 1 )     -   4) Solid algae residues were filtered out from the ethanol         extract (vacuum filtration). (Stage 2, FIG. 1 )     -   5) The ethanol extract from the previous stage was placed into a         separatory funnel (2 L), 300 mL of heptane was added to the         resulting extract, stirred vigorously for 2 min, the layers were         separated, the top layer was carefully selected and placed in a         separate flask and about 120 mL of a green heptane layer was         obtained. (Stage 3, FIG. 1 )     -   6) Another 100 mL of heptane was added to the ethanol layer,         stirred vigorously for 2 min, the layers were separated         (ethanolic layer-lower, and heptane layer-upper), the top layer         was carefully selected and combined with the heptane layer         obtained in the previous stage (˜200-220 mL of combined green         heptane layers was obtained, fraction F#1). (Stage 4, FIG. 1 )     -   7) 1 gram of silica gel was added to the entire heptane layer         obtained and, after vigorous stirring for 5 minutes, the slurry         was filtered through a layer of one gram of silica gel (instead         of silica gel, activated carbon or T41 bleaching clay can be         used). Due to variations in the properties of various silica         gels, activated carbons, and bleaching clays, the actual amounts         of the materials should be adjusted on plant. (Stage 8, FIG. 1 )     -   8) The lower (ethanolic) layer was taken from this protocol         stage 6, 350 mL of water and 200 mL of heptane were added, and         the mixture was shaken intensively for 2 mins. After about 5 min         of settling the separate phases, the top layer was carefully         selected and placed in a separate flask (˜400 mL of a green         heptane layer was obtained at this stage). (Stage 5, FIG. 1 )     -   9) The lower layer was repeatedly extracted from the above stage         with 200 mL of heptane (3×200 mL). The top layers were carefully         selected and combined with the heptane layer obtained in the         previous stage. (˜1000-1020 mL of combined green heptane layers         was obtained, fraction F#3). (Stage 5, FIG. 1 )     -   10) The extracted lower layer contained clarified polar lipids         (F#2). This fraction can be polished by 3 g of, e.g., Amaze-N         bleaching sorbent, from Helix Chromatography (15 E. Palantine         Rd. #118, Prospect Heights, IL 60070; helixchrom.com), (or         similar sorbents can be used, if needed).     -   11) The fractions obtained were evaporated in vacuum with         heating <45° C.

The extraction process exemplified above is fundamentally presented as a batch process. However, an automated process making use of appropriate controls and/or liquid-liquid centrifuges to accomplish the protocols described could similarly by employed by those skilled in this art. Automation of all of the examples/embodiments presented is possible using equipment known to people knowledgeable in the art.

The above process steps and experimental results demonstrate a highly efficient exemplary method for a liquid-liquid extraction, removing chlorophyll and a fraction of carotenoids from phototrophic (autotrophic) algal extracts, such as for Nannochloropsis or Chlorella lipids. By use of the above embodiment of a method of the disclosure, more than 99% of chlorophylls α and β, and pheophytins were removed from an ethanolic extract of Nannochloropsis (EEN), as well as about two-thirds of the carotenoids (medium polarity carotenoids). In doing so, at least 90 weight %, preferably greater than 95 weight %, more preferably greater that 97.5 weight %, even more preferably greater than 98.0 weight %, and most preferably, greater than 99 weight % of the original mass balance is fully retained and can be characterized as to its principal component parts without resorting to leaving a large portion of the mass balance as simply being uncharacterized or characterized only “by subtraction” or “by difference”. See Table 1: Extraction mass balance (composition) and Table 2: Principal components of the ethanolic extract of Nannochloropsis for mass and weight % analysis of the compositions. (Representing 99.86% of the total algal biomass by weight %.) See FIG. 4 for a spectral characterization of the Nannochloropsis ethanolic extract after removal of pigments.

TABLE 1 Extraction mass balance (composition) Extraction Mass Balance Item Value Algal paste concentration, % 27.5% Initial paste mass, g 100.0 g Solid mass (recalculated), g  27.5 g Extract volume, mL 950 Extract mass, g 9.97 Concentration (mg/mL) 10.5 Extract mass, % 36.25 Residue mass, % 63.75

TABLE 2 Principal components of the ethanolic extract of Nannochloropsis Principal groups of components Item Mass, g Weight % Non-polar lipids 1.533 15.36 Medium polarity lipids 2.605 26.09 Chlorophyll total 0.697 6.98 Carotenoids total 0.223 2.23 Polar lipids 3.62 36.23 Sugars and polar 1.294 12.97 components Total: 9.951 99.86

While viscosity measurements can vary to a degree depending on such factors as temperature, compositional concentrations of various ingredients in a formulation, etc., a viscosity reading taken for an embodiment of a Nannochloropsis extract prepared as described after combination of a polar lipids fraction with a neutral lipids fraction at 25 ° C. as described herein was noted to be @ 165,000 mPa·'s.

In summary, the products shown in Example 1 can be broken down into three principal fractions of the incoming ethanolic extract of Nannochloropsis (EEN)—1) Fraction (F#1), non-polar lipids, mainly triglycerides; 2) Fraction (F#2), polar lipids, including glycolipids and phospholipids; and Fraction (F#3), a fraction of medium polarity, comprising di- and mono-glycerides, free fatty acids (FFA's), carotenoids and chlorophyll. The clarified F#1 and F#2 fractions can be used as sources of valuable lipids high in palmitoleic and eicosapentaenoic acids (EPA). F#3, as a concentrate of natural pigments, including chlorophyll, astaxanthin, zeaxanthin, and others, also have value as food additives. Fractions F#1-3 can each be used as food additives and are valuable raw materials with high biological potential.

Example 2

A sample of a dark green paste of the algal biomass was prepared generally in accordance with a method outlined in U.S. Pat. No. 8,591, 912 B1 (see, generally, Col. 6, line 62 to Col. 9, line 3) and discussed herein (see, e.g., at [0025]). The algal biomass paste was extracted with hot absolute ethanol. Specifically, 66 g algal paste, 3×250 mL ethanol, at 75° C., 30′ while stirring at 500 rpm each, centrifugal separation at 4450 rpm for 10 minutes, yielded a specimen algal extract.

An analysis conducted of the oil extract demonstrated the principal polar lipids in the algae specimen to be: 1) glycolipids (monogalactosyl diglycerides (MGDG) and digalactosyl diglycerides (DGDG) and 2) phospholipids (phosphatidlycholine, phosphatidylethanolamine, and phosphatidylinositol) (See Table 3, herein.)

TABLE 3 Item Mass, g Weight, % Group Sample mass 66.1 n/a Quantification (wet algae paste) Dry algae (calculated) 15.87 100 Quantification Dry* residue after extraction 9.32 58.7 Quantification Crude extract mass 6.56 41.3 Quantification Non-Lipid Components 1.95 12.3 Components Non-polar lipids** 1.11 17 Lipids Glycolipids*** 1.76 11.1 Lipids Phospholipids**** 0.78 4.9 Lipids Chlorophyll 0.75 4.74 Pigments Carotenoids 0.21 1.33 Pigments *permanent weight on drying at room temperature (final moisture was not tested) **TAG, DAG, FFA, Phytosterols ***Glycolipids (AMGDG, MGDG, DGDG, SQDG) *Phospholipids (PC, PE, PI, PA, PG)

An embodiment of a bioavailable, low chlorophyll content, polar lipids-rich, LC-PUFA-rich, Omega-3 oil rich oil of the disclosure as quantified herein was prepared from the above starting material using the following additional steps:

-   -   1) Polar lipids were separated from a mixture of non-polar         lipids, chlorophylls, and other components based on differences         in polarity.     -   2) Chlorophylls were bleached from the remaining non-polar lipid         components using well developed protocols for vegetable oil         bleaching generally as described in Example 1 above; and e.g. 1         gram of silica gel was added to the entire heptane layer         obtained and, after vigorous stirring for 5 minutes, the slurry         was filtered through a layer of one gram of silica gel (instead         of silica gel, activated carbon or T41 bleaching clay can be         used). Due to variations in the properties of various silica         gels, activated carbons, and bleaching clays, the actual amounts         of the materials should generally be adjusted on plant.     -   3) The polar lipids fraction of (1) above was combined with the         bleached non-polar lipids of (2) above.

A bioavailable polar lipid-rich, low chlorophyll-containing oil composition having a generally low viscosity and with a nearly clear to light brown color was obtained. See FIG. 5 for spectral analysis. The composition was a waxy solid at ambient temperature of @ 70 degrees Fahrenheit. The composition melts when warmed and exhibits low viscosity when blended with other oils such as triglycerides and the like.

Example 3

Use of an extraction column/mechanical cartridge. 1) 58.85g of dry algal powder of Nannochloropsis (water content 1.2%, Karl Fishier) were placed into a stainless-steel cartridge (ID 25 mm, L 150 mm, V 75 cm3).

-   -   2) The thermostated extraction column filled with the algal         powder was kept at 90 degrees C. during the extraction.     -   3) Dry ethanol (0.1% (w/w) water, KF) at 90 degrees C.         (preheated in a heat exchanger), was pumped through the         extraction column at a flow rate of 4.0 ml/min (0.8 ml/min/cm2),         total pumped volume 210 ml. he eluate (extract) appearing as a         dark green liquid was collected. Total extracted mass was 15.91         g, dry residue weight (extracted algae), 42.85g. Mass % of the         extract was 27.1%.

Once the lipids portion has been separated from the chlorophyll containing fraction of the biomass, i.e., the chlorophyll containing fraction has been removed or substantially reduced in the lipids portion, as shown by the process as exemplified above, the resulting extract that is now low in, or devoid of, chlorophyll, can be further fractionated using, e.g., liquid-liquid protocols as described in Examples 1 and 2 to afford clean fractions of the other components such as the polar lipids, non-polar lipids, etc.

An analysis of the oil composition of embodiments of the bioavailable oil of the disclosure made using the above processes described herein demonstrated that oils having the following components and features (column 1), and component ranges (column 2), as set forth in Table 4 were obtained from algal biomass:

TABLE 4 Components/ Ranges of Features Components of of Exemplary Disclosed Composition Compositions Total Lipid concentration in the >90% >75% oil product Polar Lipid fraction of lipids −70% >20% Total Omega 3 content in oil −30% >20% product Total EPA content in the oil −30% >20% product Glycolipid concentration −60% >30% as % of polar lipid Glycolipid as % of oil product −40% >20% Phospholipid as % of polar lipid −40% >20% Phospholipid as % of oil product −25% >10% Total chlorophyll concentration <0.1%   <4% in oil product Total polysaccharide content  <1%  <4% (%) in oil product Color/Capacity? Dark Amber- Dark Amber- Clear Clear

Modest variations in the weight % of components and other characteristics of the oil disclosed in this application may be obtained by alterations to the process employed, as is known to those skilled in this art. However, preferably the weight % of the polar lipid fraction of the total lipid concentration of the produced oil exceeds 20%, preferably exceeds 30%, more preferably exceeds 40%, even more preferably exceeds 50%, and still more preferably is about 70% or above. Also, preferably, the weight % of the chlorophyll concentration in the oil product is less than 4% of the weight of the total oil product, more preferably, it is less than 3.0%, yet more preferably, it is less than 2.0%, even more preferably, it is less than 1.0%, 0.75%, 0.50%, 0.2% and still more preferably, it is 0.1% or below. Also, preferably, the weight % of the polysaccharides concentration in the oil product is about 4% or less of the weight of the total oil product, more preferably, it is less than 3.0%, yet more preferably, it is less than 2.5%, 2.0%, even more preferably, it is less than 1.0%, 0.5% or below. Additionally, the weight % of glycolipids as a weight % of total polar lipids exceeds 20%, preferably exceeds 30%, more preferably exceeds about 40%, even more preferably exceeds 50%, 60%, 70% and still more preferably it is 80% or above, and its weight % of the total oil composition exceeds 10%, more preferably 20%, and still more preferably is about 25% or above. Additionally, the weight % of phospholipids as a weight % of polar lipids exceeds 20%, more preferably exceeds 30%, and still more preferably exceeds 35%, and their weight % of the total oil composition exceeds 20%, more preferably 30%, and still more preferably 40%. While not being bound by any particular theory, applicant believes that by the combination of these characteristics, including very low chlorophyll concentration in the oil product, an attractive, lightly colored, nearly clear, to amber, up through darker amber color is produced, and in a preferred embodiment, nearly clear to amber. Also, EPA concentration of the total oil product content is at least 20 weight %, more preferably at least 25%, and still more preferably at least about 30 weight % or greater is produced. Similarly, the Omega-3 content of the oil product is at least 20 weight %, more preferably at least 25 weight %, and still more preferably at least 30, 40 weight % or greater is produced. Considered as a whole, the weight % of LC-PUFA content of the oil product at least 20%, at least 25%, 30%, 40% and 50%.

Elevated bioavailability of the resultant oil is also achieved. Moreover, unlike some prior art methods of extracting and fractionating microalgae, the disclosed method does not involve aggressive chemistry such as the use, e.g., of strong mineral acids which frequently destroy polar lipids and can significantly degrade other valuable fractions of the algal biomass.

Also obtained in embodiments of processes of the disclosure are powders of non-lipids components such as polysaccharides of the crude ethanolic algal extracts. See FIG. 3 .

It should also be noted that for LC-PUFA, Omega-3, EPA-containing, high polar content oils of the disclosure, there is a greatly reduced weight % of the following chlorophylls: 1) chlorophyll a, 2) protochlorophyll a, and 3) methylchlorophyllide. Preferably, the weight % of the chlorophylls of the composition is less than 4%, preferably less than 3%, yet more preferably less than 2%, even more preferably less than 1%, still more preferably less than 0.5%, 0.5%, and still even more preferably less than 0.1% of the total weight % of the composition.

In another embodiment of a composition of the disclosure, the composition has an enhanced weight % of several other ingredients, including carotenoids, e.g., carotenes (α and β), and zeaxanthins (yellow pigments), and canthaxanthin and zeaxanthin (reddish pigments), with total carotenoids making up more than 0.5% of the total weight of the extract and preferably more than 1%.

In other alternative embodiments of the disclosure, the bioavailable, high polar-lipids containing, EPA-containing, low chlorophyll content oil compositions, embodiments of which are disclosed herein, can be presented as formulations in which other useful ingredients are added. These other useful ingredients can be added alone, or in one or more combinations, e.g., combinations with other essential oils, dietary supplements, health supplements and the like. Specific examples include, but are not limited to—1) other omega 3 containing oils or components such as DHA and EPA (e.g., in the form of the neutral lipids extracted as a product in the instant invention or externally sourced), the lysolipids from the instant invention, or externally sourced, ethyl esters of DHA or EPA; 2) antioxidants such as carotenoids, including astaxanthin, lutein, zeaxanthin, lycopene, carotenes (alpha and beta), cryptoxanthin, and mixture thereof (including the carotenoid fraction of the instant invention); 3) vitamins, such as vitamin C and D; 4) cannabinoids, such as cannabidiol (CBD), and 5) other combinations. It is understood that such formulations including some of these species with less-colored and/or less-viscous compositional profiles, may reduce the overall color profile and viscosity of formulations which include the fatty acid compositions with high polar lipid, high glycolipid, and low chlorophyll concentrations prepared by embodiments of the processes disclosed herein. Thus, this may be achieved, e.g., by inclusion of non-polar lipids, either added back in from original biomass stock, or from an external source, or by preparation of formulations which demonstrate such attributes.

Examples of nutraceutical formulations including blends of the polar EPA fraction described above with DHA (Omega-3) can beneficially be in a ratio from 10-90 to 90-10, wherein preferable levels of the polar EPA formulation component being mixed at 20-50%. Uses for such formulations include both use as a key food supplement/nutraceutical in its own right for cardiovascular health, mood, anti-depression and more, and also as a delivery system for other neutral lipids and components it is formulated with. This can be DHA, other neutral forms of EPA, or mixtures thereof. Astaxanthin at levels of 10-60% can also be beneficially formulated, with preferable levels at 10-30%, either with pure polar EPA lipids or blends thereof with neutral EPA and/or EPA. Another component that could be beneficially added to such a formulation is coenzyme Q10 at levels of around 1-50%, preferably about 2-20% on the polar EPA, either pure or in any of the above formulations.

In addition to other attributes, formulation blends with added neutral lipids, e.g., can be useful to target various viscosity levels, such as 50,000 cps, preferably less than 10,000 cps, more preferably less than about 2,000 cps, and most preferably, about 300 cps or less.

In view of the above, it will be seen that the several objects and advantages of the present disclosure have been achieved and other advantageous results have been obtained.

As various changes could be made in the above constructions without departing from the scope of the disclosure, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. 

1. A method for production of a low chlorophyll, enhanced polar lipids content oil composition comprising the steps of: a. obtaining an algal oil or extract comprising both polar and non-polar lipid fractions, and having a chlorophyll concentration, wherein the polar lipid fraction is contained within a polar solvent, and the non-polar lipid fraction is contained within a non-polar solvent; b. using polarity characteristics of the polar and non-polar lipid fractions to segregate polar from non-polar components in the algal oil or extract; c. removing substantially all of the chlorophyll concentration from the non-polar containing fraction; d. removing the polar solvent from the polar lipid fraction and removing the non-polar solvent from the non-polar lipid fraction; and, d. re-combining the polar and non-polar lipid fractions to produce the low chlorophyll content, enhanced polar lipids oil composition.
 2. The method of claim 1 wherein removal of the chlorophyll concentration is achieved via use of a bleaching agent.
 3. The method of claim 1 wherein removal of the chlorophyll concentration is achieved via use of adsorption-filtration.
 4. The method of claim 1 wherein the method does not include the addition of strong mineral acids in any step of the process.
 5. The method of claim 1 wherein the polar solvent is less than 10% water by volume.
 6. The method of claim 1 wherein the polar solvent is less than 5% water by volume.
 7. The method of claim 1 wherein the polar solvent is less than 1% water by volume.
 8. The method of claim 1 wherein removal of the polar solvent and removal of the non-polar solvent are accomplished, at least in part, by evaporation.
 9. The method of claim 1 wherein removal of the polar solvent and removal of the non-polar solvent are accomplished, at least in part, by heating.
 10. The method of claim 1 wherein removal of the polar solvent and removal of the non-polar solvent are accomplished, at least in part, by applied vacuum.
 11. The method of claim 1 wherein the step of using polarity characteristics of the polar and non-polar lipid fractions to segregate polar from non-polar components in the algal oil or extract is performed using multiple sequential extractions using solvents of different polarity.
 12. The method of claim 1 wherein the polar lipid fraction comprises DHA.
 13. The method of claim 1 wherein the step of removing substantially all the chlorophyll concentration from the non-polar lipid fraction is such that the final composition comprises less than 20 ppm of chlorophyll.
 14. A method for production of a low chlorophyll, enhanced polar lipids content oil composition comprising the steps of: a. obtaining an algal oil or extract comprising a chlorophyll concentration and both polar and non-polar lipid fractions, wherein the polar lipid fraction is held within a polar solvent, and the non-polar lipid fraction is held within a non-polar solvent, and further wherein polar and non-polar lipids are more than 75% of the combined mass of the polar and non-polar lipid fractions; b. using solvents of varying polarity, as well as polarity characteristics of the polar and non-polar lipid fractions, to separate polar from non-polar components in the algal oil or extract via multiple sequential extractions; c. removing substantially all of the chlorophyll concentration from the non-polar containing fraction; d. removing any remaining polar solvent, non-polar solvent, and solvents of varying polarity; and, e. re-combining the polar and non-polar lipid fractions to produce the low chlorophyll content, enhanced polar lipids oil composition.
 15. The method of claim 14 wherein the polar lipid fraction comprises DHA.
 16. The method of claim 14 wherein the step of removing substantially all the chlorophyll concentration from the non-polar lipid fraction is such that the final composition comprises less than 20 ppm of chlorophyll.
 17. The method of claim 14 wherein water is not used during a first extraction of said multiple sequential extractions.
 18. The method of claim 17 wherein water is not used during a second extraction of said multiple sequential extractions.
 19. The method of claim 14 wherein the non-polar lipid fraction comprises ethyl esters.
 20. A method for production of a low chlorophyll, enhanced polar lipids content oil composition comprising the steps of: a. obtaining an algal oil or extract comprising a chlorophyll concentration, a non-polar lipid fraction, a medium polarity lipid fraction, and a polar lipid fraction, wherein the non-polar lipid fraction is held within a non-polar solvent, and the medium polarity lipid fraction and polar lipid fraction are held within a polar solvent; b. using solvents of varying polarity, as well as polarity characteristics of the polar and non-polar lipid fractions, to separate the polar fraction and medium polarity lipids fraction from the non-polar lipid fraction, and then to separate the medium polarity lipids fraction from the polar lipids fraction via multiple sequential extractions; c. removing substantially all of the chlorophyll concentration from the non-polar containing fraction and from the medium polarity fraction; d. removing any remaining polar solvent, non-polar solvent, and solvents of varying polarity; and, e. re-combining the polar lipid fraction, medium polarity lipid fraction, and non-polar lipid fractions to produce the low chlorophyll content, enhanced polar lipids oil composition.
 21. The method of claim 20 further comprising re-combining the polar lipid fraction, medium polarity lipid fraction, and non-polar lipid fraction to produce the low chlorophyll content, enhanced polar lipids oil composition. 